Launch HN: Remora (YC W21) – Carbon capture for semi trucks
I'm Paul, one of the co-founders of Remora (https://remoracarbon.com). Remora is building a device that captures the carbon emissions from a semi truck. Our device mounts between the truck and its trailer, attaches to its tailpipes, and captures at least 80% of its carbon emissions. We will sell the captured carbon dioxide to concrete producers and other end users, helping companies earn new revenue while meeting their climate commitments.
We decided to start Remora because we believe electrification won't work for long-haul trucking. Bill Gates agrees: “Even with big breakthroughs in battery technology,” he wrote, “electric vehicles will probably never be a practical solution for things like 18-wheelers" [1].
Before Remora, my co-founder, Eric, built hydrogen and electric semi trucks. He saw first hand that these trucks have far less payload capacity and range, plus the batteries lose > 40% of their range in cold weather [2]. We also knew that electrification means building a new network of stations with enough charging capacity for semi trucks, replacing every truck on the road, and overhauling the grid, which is still 63% fossil fuels in the US [3]. So we thought:
Why can't we just capture the carbon emissions from the trucks' tailpipes?
Turns out, my co-founder, Christina, spent her entire PhD answering this question [3]. Mobile carbon capture was first proposed about a decade ago, but academics dismissed it in favor of stationary carbon capture for power plants. The problem with stationary capture, though, is that it takes tens of millions of dollars upfront to design those systems, and they have to be tailored to a specific plant—it’s impossible to make a cheap, modular unit that can be manufactured at scale.
So Christina became the first person to test adsorbents (the materials that selectively capture carbon dioxide) in the specific conditions of diesel exhaust. Surprisingly, the adsorbent that worked best was a naturally-occurring mineral that is cheaply available in mass quantities. Christina built a proof of concept to test in the EPA’s National Vehicle and Fuel Emissions Lab, and it worked.
While I was finishing my senior year at Yale, I read Christina’s dissertation online. I called her up to ask a bunch of questions and we hit it off. After more conversations, I wrote her a business plan and convinced her to quit her new job at the EPA to start Remora. Then, we sent a blurb to every professor at the top 15 engineering schools, interviewed ~ 50 engineers, and found Eric.
Now, we’ve completed our first working prototype and we’re currently testing it on our truck. Here’s how it works: First, we condition the truck’s exhaust to lower its temperature and humidity, then we run it through a bed of pellets that selectively captures carbon dioxide, letting the other gases escape. When the bed is saturated, we heat the pellets to release the carbon dioxide, which we compress into a tank inside the device. To ensure continuous operation, the device includes two beds: while the first is heated, the truck’s exhaust flows through the second; when the second is saturated, they switch, and so on. This process is very energy efficient because we’re able to use the waste heat from the truck’s exhaust to heat the pellets.
Our first units will be capturing carbon dioxide on customers’ trucks by August. By the end of the year, we’ll have 40 units on the road capturing ~ 100 metric tons of carbon dioxide per week—the equivalent of planting 248,000 trees [5]. We will start by selling this carbon dioxide to concrete producers and other end users, but as we grow, we will earn tax credits for permanently sequestering the carbon dioxide deep underground.
Long term, if we pair our technology with biofuels, we can make a truck carbon negative. We also hope to apply it to other hard-to-electrify forms of long-haul transportation, like cargo ships.
We’re excited to hear...
204 comments
[ 3.8 ms ] story [ 212 ms ] threadHow much weight will this add to the vehicle?
How big is the device?
How often does the truck driver have to 'empty' the device?
How are you planning to set up a distribution network to get the captured carbon from the truck to the concrete producers?
edit: typo
The device currently weighs 3,200 pounds without carbon dioxide and 5,000 pounds loaded with carbon dioxide, and it'll get a lot lighter over time. We believe our device will qualify as “idle reduction technology” under federal law, and as “near-zero emission” under California law, meaning a truck with our device can weigh up to 80,550 pounds anywhere in the United States, and 82,000 pounds in California (above the usual 80,000 lbs). So the hit to payload capacity will be less than the weight of the device.
The device is 0.30 meters x 2.27 meters x 3.14 meters. It covers the back of a semi truck.
The driver currently has to offload the CO2 every 600 miles, and we'll be significantly improving range over time.
For our early partners, we'll install a CO2 tank at a distribution center or another facility of their choosing. We'll install our devices on trucks that do round trips to and from the facility so that they can offload the captured CO2 at the end of the day. Then, we'll transport the CO2 from the facility to a nearby concrete producer in a tanker truck (equipped with our device). As we grow, we will install CO2 tanks at truck stops along our partners' highest-density routes. Our network will grow organically as we begin to work with more and more companies.
How much of a problem are things in the exhaust like sulfur and particulates? Do they end up poisoning or clogging the adsorber after some time, or does regeneration burn them off? Could you remove some of the particulates from the exhaust to save our lungs too?
A truck can do at least 100k to 120k miles per year.
So 63k to ~76k liters per year per truck. 63k * 2.6kg equals about 163.6 metric tons per year on the low end.
600 miles isn't the full tank of combustion. Sound like driver is swapping tanks or something at one of their stops.
Final q (other than cost): how much exhaust backpressure?
This is just approximate, since fuel has a bunch of H and S and other crap, so it's not 100% C. But, yes, these figures are in the right ballpark.
Now the jokes' on me.
1 kg of carbon from fuel + 1.75 kg of O2 from aith = 2.75 kg of CO2.
There's more energy in the hydrogen bonds, not the carbon-carbon bonds, right? Just adds insult to injury, if you ask me.
To offload, the driver attaches a hose, which connects to an offloading tank, and the CO2 is pumped from the tank inside our device to the much larger offloading tank. We liquefy the CO2 as it comes off the truck for storage in the tank. Luckily, the pump doesn't use much energy, and our early partners are using renewable energy to power the pump! We plan to continue using
There are different exhaust compositions for the engines on these different vehicles, in part because they use slightly different fuels. So there will be some research and work to do before jumping into the next market, but we love developing technology that has never existed before, we are so excited!!
Edit: full this device is only 6% of the max (80000lb) weight, maybe 15% weight on just the tractor.
The more inefficient you make the trucks, the more carbon you'll capture!
Carbon negative, you say? Easy solution to climate change then: Let's just put millions of your trucks on the roads and have them drive around all the time. /s
This is just a clever way to get trucks and farms to do the work with the infrastructure we have (mostly) in place, rather than a radical reimagining of our energy infrastructure.
Not that I've seen proof this process would work, but I think that's the proposal.
It just doesn't make sense to emit all the CO2 to then recapture and sell it to someone. First, it's awefully inefficient, and second, do you think there's an infinite amount of demand for CO2 at a high enough price that it makes sense to jump through all these hoops?
Unfortunately, the best solution for climate change is the least sexy, and therefore techies, VCs and the media don't jump on it. 1) Reduce emissions by "boring" things like solar power and less livestock agriculture, 2) increase the existing CO2 sinks that already exist in nature (forests and coastal areas).
Biofuels like corn to ethanol might take too much land area, but the potential to get biofuels from algae or poop (yes poop is a great biofuel) require no additional land area and are very efficient. A biofuel research study at U of Michigan showed a biofuel process that produces -1 g/ gallon burned GHG emission effect. We don't pretend to know exactly how to scale up biofuels but luckily there is a lot of research in progress on this!
The other thing we could potentially do is convert the CO2 directly back into a fuel, so the offload and fueling station is completely done at the same truck stop!
Lastly we also agree that our technology does not allow society to exist exactly as it is now, we will always support reducing energy consumption where possible and better land use to let nature sink tons of CO2.
Don't get me wrong, I think it's good that people are working on CO2 sequestration, but I just get triggered if I read something like "carbon negative trucks" which just is 101 greenwashing and gaslighting.
I'm pretty interest how carbon negative is greenwashing when there could actually be less carbon in the atmosphere, will be verified with a life cycle analysis, especially since we can fit on a truck that already exists so the truck manufacturing CO2 is already something that's been spent.
My trigger is when things are called zero emissions, because no electric car, solar panel, or windmill are zero emissions.
Managed grazing has some good points, but it's mixed with a lot of pseudoscience and cult also. In the end, we need to get rid of almost all livestock agriculture if we are serious about tackling climate change.
> I'm pretty interest how carbon negative is greenwashing when there could actually be less carbon in the atmosphere, will be verified with a life cycle analysis, especially since we can fit on a truck that already exists so the truck manufacturing CO2 is already something that's been spent.
It's just a bit out there. There are better and more efficient ways to reduce GHG emissions than what you're proposing. Again, it's good that people are working on new tech to sequestrate CO2, but let's talk again about selling this "carbon negative" vision once we get CO2 sequestration working on a large scale at a low enough cost.
Until then, I sincerely wish you all the best! We're all in this together :-)
We will support independent sustainability research on our solution's life cycle analysis to verify if we can be carbon negative, and if not what changes can we make to get there.
Carbon capture only works if we have viable long term solutions for the captured carbon dioxide - which isn't the easiest gas to get rid of.
What is the performance impact on the engine?
You said in another reply that it will also capture CO, NOx, and SOx. Will this replace any existing emissions equipment such as urea injection?
Our solution is complimentary with solutions like urea injection and diesel exhaust fluid!
This adds up to more volume than the original diesel— a lot more. There's no actual efficiency to be gained here, especially since trucks are more constrained by mass than by volume.
Why not use a auxiliary battery heating system that uses some kind of fuel (i.e. biofuel) for this scenario? The amount of fuel needed to heat a battery to its optimal operating temperature during cold weather is probably orders of magnitude less than the amount of fuel needed to propel a truck, so the carbon emissions would be minimal. The same system could also be used for driver cabin heat.
Hopefully that makes sense.
From the vehicles I have actually built and weighed there is a much larger increase in weight than you are predicting.
Tesla model 3 curb weight 3897 lb and 200 mile highway range. https://www.caranddriver.com/tesla/model-3
Toyota camry curb weight 3340 and 616 mile highway range. https://www.caranddriver.com/toyota/camry/specs
You can see that 1/3 the range for the same weight, and this only gets worse as the vehicle gets heavier. For class 8 trucks wind drag is a very small percentage of the losses, rolling resistance from weight is the largest loses. So I don't think linear distance scaling you assume adds up.
Its going to be an interesting transition and we know that electric trucks will be great for some use cases but its going to take a mix of solutions, especially in countries where their grid infrastructure is no where near as robust as ours.
> For class 8 trucks wind drag is a very small percentage of the losses, rolling resistance from weight is the largest loses.
According to this source[1], for class 8 trucks at max gross weight on level road, aero and rolling resistance losses are the same around 50MPH, and aero dominates after that. Is that source wrong, or out of date? Source says "aerodynamic drag and tire rolling resistance are major contributors to energy loss" - neither is a "very small percentage".
From everything I've read publicly, EV semis won't have transmissions or transaxles, just motors on the drive shafts (4x120lbs). Not sure where you get 6k lbs, even including the "added copper wiring".
I can totally see a 1-2 ton payload advantage for diesel+CCS over EV semis when the required range is 500+ miles, just not a 15k lbs advantage. Ultimately the market will decide what tech to use for different routes though, and I agree that a variety of solutions will be utilized.
[1] https://www.nap.edu/read/13288/chapter/7#79
There are also some range and power losses due to increased internal cell resistance when the battery is cold, but the effects of this diminish as the battery warms up with use. Actual range loss for an EV semi in the cold should be minor, probably similar to the range loss for ICE semis in the winter.
https://news.ycombinator.com/item?id=26419981
That would be a pretty major infrastructure project, though.
2. The tank requires 8 ft x 8 ft (on a 16 ft x 16 ft pad). The pump and refrigeration unit are small and are mostly off, so they don't use a lot of energy. Our early partners are also powering them using renewable energy, to further help our lifecycle emissions reduction.
3. Our understanding is that the price of CO2 varies geographically, so it will depend on where in the country we're capturing CO2. We're still testing the exact purity of our CO2, but it's definitely > 95% and we believe we can get it to > 99%. What purity does your company use?
4. It only takes trucks a few minutes to offload the CO2. They don't have to unload or reload anything - they just have to attach a hose and the device pumps the CO2 into the offload tank. We want to make this as easy as possible for drivers. Our first partners are actually very large companies that own private fleets of semi trucks and have aggressive climate commitments, so they have a little bit more wiggle room to test new technology!
5. That's exactly our plan. In the short term, we'll be earning revenue by selling to the concrete producers or other industrials. In the medium term, we'll be mainly be earning revenue by permanently sequestering our CO2 deep underground.
Let me know if I missed anything!
Our process is 99% purity.
I think you are referring to only electrical trucks; Hydrogen still carries on load and doesn't have the same operational cold weather challenges.
Have you ever met a truck mechanic who didn't perpetually smell of diesel? Do you want them working with explosive gasses instead?
Hydrogen leaks much faster and dissipates quickly into the atmosphere (unlike gas/diesel) defusing the risk of combustion (flip side is much harder to contain and systems need to be tighter). However if it gets caught under pressure it has a risk to it.
Hydrogen is 4% to 75%. This means almost any concentration of hydrogen and oxygen is flammable.
To your flammability point - yes that is true - there are other advantages to Hydrogen being that it lighter than air and dissipates relatively quickly (diffusing the explosion risk) and that it is no toxic. Where as in the case of a car accident gasoline pools underneath the car and remains on site and a continued risk.
There are disadvantages to Hydrogen as well - the flammability has to be managed, its a pernicious molecule and causes embrittlement. All solvable through engineering.
For hydrogen to work in the trucking space you work on end-to-end systems, therefore negating the need to change the entire infrastructure. You target 80% of the trucking industry and leave the last might to more carbon intensive mechanisms.
I think the approach that best works for your company - and the one that I natively believe in: We need all of these technologies to change the future narrative and not fall into a situation where the new technologies are competing against each other.
If you can remove the technology risk/operation risk and start deploying these systems quickly - you have a very promising opportunity ahead of you. Don't waste time trying to compete against EV or Hydrogen. All of the above is the approach.
So, in the end, how much is captured on average ?
And once it is captured, in which conditions does it stay captured ? for how long ?
This is right in my interests -- investing directly in companies trying to combat climate change. Does anyone know much about them? I'm considering dropping them a line and seeing if I can invest in the fund as well.
1. https://lowercarboncapital.com/
Maybe a chain like Blaze Pizza
There are also a lot of technologies in progress to use CO2, such as turning it right back into synthetic fuels!
The list goes on and seems to be growing by the day.
From what I’ve read this is a technique to lower the cost of concrete, so the added value would be capped at roughly whatever the price of concrete without CO2 is. There’s also the possible substitute of CO2 derived from other sources with a lower recovery cost, such as sequestration at a plant as you mentioned. How much can be charged for captured CO2 and what’s the market price?
The big difference between plant sequestered CO2 seems to be the need to sweep up and store the CO2 which will be stored across the country. How will the infrastructure for offloading into the tank and delivering the captured CO2 work? How many tanks and how many trucks for moving the liquified CO2?
I think your comment on the concrete capped price assumes that the price for producing CO2 does not increase. If current concrete produces CO2 (which it does produce a lot) and CO2 gets taxed, it makes concrete that sequesters CO2 very financially viable even if it cost more than the current concrete market price. Plus I know I would pay more for concrete that sequesters CO2 so maybe that's another competitive advantage that allows it to cost slightly more.
Plants are great and we love and support using our lands more effectively, but there is not enough land to store the CO2 that has been emitted over the last century from fossil fuels, and keep up with the increasing energy demand from population growth as well as developing nations. So plants cannot do this on their own.
There is such a large market for CO2 (and its growing!) that we can find users of the CO2 very near our storage tanks. For example one pilot program we are planning right now has a CO2 concrete producer only 6 miles away! Of course our CO2 hauling trucks will have our device and we will get better and better at leveraging existing infrastructure (pipe lines and trains) to transport CO2 efficiently.
Always interested to hear your experience.